Treatment of aluminium to render it unalterable.



UNITED STATES manna carton.

FRANCESCO JPUCILLO, E GENOA, ITALY.

TREATMENT OF ALUMINIUM TO IT UNALTERABLE.

icence.

No Drawing.

To all whom it may concern Be it known that I, Francesco PUCILLO,

subject'of the King of Italy, and resident of Conservatore del Mare 9--13, Genoa, Italy, engineer, have invented a new and usefu Improved Treatment of Aluminium to Render it Unalterable, of which the following is a specification Aluminium is subject to attack not only by acids and alkalis but also by man other agents, a fact which limits considerably the application of this metal.

My invention relates to a treatment of aluminium for the purpose of making it incapable of being attacked by all external influences of whatever nature, even at very high temperatures. The treatment may be applied to castings, sheets, wires or tubes, in fact to any object of aluminium.

The process of treatment involves the followinr. operations:

1. The aluminium object which is to be rendered unalterable is first treated with an alkaline solution 15-20%, then neutralized by acidified water and Washed with pure water with a view to make the objects adapted for the subsequent treatments.

2. It is then treated with solutions of chloride beginning, for example, with clorid of iron 2.54%, chlorid of zinc 0.81%, chlorid of tin 65-10% and chlorid of ammonium 05-10%, of which solutions the rest is water. These proportions may somewhat vary according to the quality of the aluminium.

3. These operations are succeeded by a. treatment of the object with an ammoniacal solution of copper chlorid with addition of 1%ftartrates, such as sodium tartrate and calcium tartrate about 49%. By this treat,- ment there will be formed upon the surface of the aluminium a coating of metallic oxidation which is so adherent to the metal that it cannot be separated therefrom. This coating is strengthened by means of the following o erations.

4. The object is next subjected to the action of alcoholic zinc acetate about 5% and neutralized by an aqueous solution of sodium carbonate. potassium carbonate or other alkaline carbonate.

5. The next operation is a treatment with acidified water (for instance water acidified with sulfuric or nitric acid 35%) and the object is then carefully washed and cleaned and then heated to a temperature above 100 Specification of Letters Patent.

I some other energetic alkali.

Patented Mar. 2, 1915.

Application filed February 6, 1911. Serial N 0. 806.982.

U. (advantageously 350 C.) By the treat ment carried-onto this point there is formed at the surface of the aluminium a compound .of this metal with the metals and com- I pounds of metals with which the obiect has been treated: the coating thus produced, and which is of black lustrous color is strongly united with the aluminium and able to support anv mechanical working without being detached from the metal. If the treatment he now stopped the object is adapted to receive on its surface any metallic deposit; for example it may be coated with nickel, cohalt, silver, or the like, either electrolytically or otherwise; it may even be varnished. This is an important result achieved bv the invention, but if the object is to be rendered completely incapable of being attacked by external infiuences. the treatment is continued in the following manner:

6. The object is washed with a solution of crude mineral oil, drying oils and-balsams, mixed with a. small proportion of gum-resins. The mixture, before being used. should be treated with ox gen or with an appropriate oxidizing agent. This oxidation is necessary to prepare the liquid for its transformation upon the surface of the aluminium into an insoluble and inattackable coating of carbon and hydrocarbon.

7. Finally the obi'ect is completely dried by heat and Washed with hot caustic sodao The aluminium, after being subiected to the complete treatment such as has been just indicated. resists the attack of alkalis, acids and all other substances, notablv sea-water. It can be painted and varnished and the paint or varnish can be subsequently removed by means of hot alkali or other detereent w thout fear that the surface of the object will be in any way altered. Aluminium treated in this manner becomes applicable for electric cables, for marine naval cons ructions and for many other purposes. I What I claim is:

1. A process'of treatment of aluminium of an valkaline carbonate; (e)- then treating it by acidifiedwater, washing and cleaning it carefully and heating it to 'a temperature above 100 C.

2. A process of treatment of aluminium cen iet in; (a) a ng the m on um object with an alkaline solution, neutralizing it by acidified water and Washing with pure Water; (1)) then treating said object with solutions .05 Qhlgrids; (0.) then trea ing it i h an ammomacal s utlon o 0.0 per ch e d ith addit eo of tartrat s; (ri ea i g i af erw rd by almah lie Z e ace e nd n trwizing t by an aqueous eelution of an alka ine carbon te; (4%) then trea ing t y ac d fied water, s ng and cleaning i care u y and heatmg t to 8 temperature above 100 (3.; (f) then washing the object with a hot solution of crude mineral oil, drying oils and balsams, mixed with a small pr portion f gum-r sins, the mixture being treated with an oxidlzing een b or being used; (9) finally, cometely drying the object by heat and washp ing it with a bet ner alkali- In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses; this 2lst day of Januern 18. .1-

' DE M- Mas ns ALcmE FABE. 

